smartd

“Ka-chunk... ka-chunk... ka-chunk... tick... tick... tick... Ka-chunk... ka-chunk...” That's just not a sound you ever want to hear coming from a hard drive. It's the sound of a hard drive trying to move it's read/write heads into a position that they don't seem to want to go to or its trying to read a sector that just isn't there anymore. Of course, modern hard drives have come a long way and are amazingly reliable, but if you work with computers long enough, you're bound to have one fail on you.

This article describes what actions might be taken when smartmontools detects a bad block on a disk. It demonstrates how to identify the file associated with an unreadable disk sector, and how to force that sector to reallocate.